Welcome to Bimmerfest -- The #1 Online Community for BMW related information! Please enjoy the discussion forums below and share your experiences with the 200,000 current, new and past BMW owners. The forums are broken out by car model and into other special interest sections such as BMW European Delivery and a special forum to voice your questions to the many BMW dealers on the site to assist our members!

E46 (1999 - 2006) The fourth generation 3 Series (E46 chassis) was introduced in 1999 and set the standard for engineering and performance during it's years of production including being named to Car & Driver's 10 best list every one of those years! ! -- View the E46 Wiki

Hey all....well I just joined this forum. I bought a '03 325xi about 6 months ago and was interested in doing some engine work. Obviously its not a m3 and I'm not gonna pull 500 hp out of it w/o a major overhaul. Was wondering if you guys had any suggestions on things to do...things not to do. Good places to find parts, that sorta stuff. Thanks

Congrats on the car. As for the answers, your best bet is to do a few searches on these boards. That question has been asked, answered, re-asked, and reanswered at least 100 times. What you're probably going to find is that there's not a lot you can do to these engines. BMW did a pretty good job tuning the engines straight from the factory.

Adding a K&N air filter won't help it might actually hurt. Cold Air Intakes don't seem to add any extra horsepower, but they add extra noise which makes you feel like you're going faster. Other than adding a turbo to your car, there's probably not much else you can do.

Adding a K&N air filter won't help it might actually hurt. Cold Air Intakes don't seem to add any extra horsepower, but they add extra noise which makes you feel like you're going faster.

Please, no opinions that are not backed up by numbers or experience. I don't have the first, but have the latter and would actually encourage him to try one of the "cheaper" intakes (AFE, Conforti, ECIS etc.).

Original poster, indeed do a search and you will find lots of opinions, fewer facts but it should help you decide anyway.

My personal advice would be to do a BMW driving school with your local CCA chapter - it will enable you to extract more your vehicle's stock amazing performance. I'm assuming you haven't done one of these before - but if you want more info PM me and I'll be glad to answer more of you questions.